The present invention relates to a method for manufacturing a photovoltaic module, of the type comprising at least two electrically connected photovoltaic cells, said module comprising an insulating substrate covered with a layer of a first conducting material; the method comprising the following steps: a) forming, on the layer of first material, a groove defining first and second lower electrodes, isolated from one another; and b) forming, on each of said lower electrodes, a stack comprising at least: an upper electrode formed by a layer of a second conducting material; and at least one photo-active layer positioned between the lower and upper electrodes; each of the first and second lower electrodes respectively forming a first and second photovoltaic cell with the corresponding stack.
A photovoltaic module is an electronic component which, exposed to light, produces electricity. Such a photovoltaic module typically comprises several electrically connected photovoltaic cells. Each cell includes at least one photo-active material, i.e., able to produce electricity from light. Such a material is for example an organic semiconductor.
Photovoltaic modules of the aforementioned type are described in documents U.S. Pat. No. 7,932,124 an EP 2,478,559. Each cell of such a photovoltaic module is formed by a stack of strips, including a photo-active layer between two electrodes, said stack of strips being positioned on a substrate.
Such a stack, called active area, is separated into adjacent active areas by a so-called inactive area. Said inactive area allows electric isolation of the lower electrodes of two adjacent cells while connecting the upper electrode of each cell to the lower electrode of an adjacent cell. A photovoltaic module is obtained by forming several cells thus connected in series.
Generally, in large-scale production methods, the stack layers are made using a wet method, i.e., by depositing a liquid formulation followed by a passage to the solid state.
The performance of the photovoltaic module particularly involves producing the narrowest possible inactive areas, to maximize the size of the active areas. The geometric fill factor (GFF) of the photovoltaic module is defined as a ratio between the sum of the areas of the active areas of the photovoltaic cells and a total area of the substrate. The higher the GFF is, the better the electrical performance of the photovoltaic module is. In particular, obtaining a high GFF requires mastering the geometry of the electrical connections.
However, the rheological and wettability properties of the formulations, as well as the physical properties of the substrates, induce edge effects on the strips deposited by the wet method. In document U.S. Pat. No. 7,932,124, the layers of the stack forming each cell are in particular made with decreasing widths, so as to arrange a stair-stepped lateral offset. Such a production method makes it more complex to implement through large-scale production methods and contributes to decreasing the size of the active areas.
In document EP 2,478,559, the stack is first made uniformly on the entire module, then different grooves are formed in the layers in order to form the inactive zones. This method requires selective ablation means, the different grooves having different depths depending on their role in the inactive zone.
The present invention aims to propose a method for manufacturing a photovoltaic module in particular making it possible to minimize the size of the inactive areas and to maximize that of the active areas.